Nitrogen cycling in high-input versus reduced-input arable farming

Abstract

Compared a high-input and two reduced-input farming systems with a rotation of winter wheat-sugar beet-spring barley-potatoes on a calcareous silt loam soil. Nitrogen balance sheets for the growing seasons of 1986-1988 showed N deficits of 0-170 kg ha-1, suggesting substantial N losses to the environment. Periods with much rainfall in 1987 and 1988, inappropriate use of animal manure and soil compaction may partly account for the heavy N losses in all systems. To increase the efficiency of mineral and organic N inputs, and to decrease N losses, soil inorganic-N concentrations should be kept low, especially in periods when losses are likely to occur. -from Authors